January 23, 2020

Varieties of Claims

Plan for Today

1) Recap: Normative vs. Empirical claims

2) Empirical Claims: causal vs. descriptive

3) Falsifiable/Unfalsifiable

Recap

AfD Arguments

  1. About 1.1 million refugees entered Germany during 2015.

  2. The vast majority of these refugees came from Syria and other parts of the Middle East.

  3. Alexander Gauland: “we don’t like the values of Islam based on sharia [law] that are not compatible with our Basic Law.”

  4. “Illegal mass migration undermines the opportunities in life for socially worse off Germans.”

  5. This influx in refugees increased violent crime.

  6. Germany should admit far fewer refugees/immigrants.

POLL

  1. About 1.1 million refugees entered Germany during 2015.

  2. The vast majority of these refugees came from Syria and other parts of the Middle East.

  3. Alexander Gauland: “we don’t like the values of Islam based on sharia [law] that are not compatible with our Basic Law.”

  4. “Illegal mass migration undermines the opportunities in life for socially worse off Germans.”

  5. This influx in refugees increased violent crime.

  6. Germany should admit far fewer refugees/immigrants.

  1. About 1.1 million refugees entered Germany during 2015. (empirical)

  2. The vast majority of these refugees came from Syria and other parts of the Middle East. (empirical)

  3. Alexander Gauland: “we don’t like the values of Islam based on sharia [law] that are not compatible with our Basic Law.” (normative)

  4. “Illegal mass migration undermines the opportunities in life for socially worse off Germans.” (empirical)

  5. This influx in refugees increased violent crime. (empirical)

  6. Germany should admit far fewer refugees/immigrants. (normative)

Varieties of
Empirical Claims

Varieties of Claims

Which varieties of claims/questions can be addressed with science?

Three dimensions

  1. Empirical vs. Normative
  2. Varieties of empirical and normative claims/questions
  3. Falsifiable vs. unfalsifiable

Some empirical claims

  1. In 2018, Canada had 0.67 firearms homicides per 100K while the US had 3.14 per 100K.

  2. The United States has more assault weapons per capita and more mass shooting victims than Canada

  3. Canada has fewer firearms deaths per capita than the US because Canada has stricter gun laws.

  4. Americans use guns in self-defense about 2.3 million times per year.

  5. People who openly carry a firearm are less likely to be victims of crimes

  6. Making it easier to legally carry a concealed firearms increases firearms deaths.

Descriptive claims:

descriptive claims:

claims about what exists (or has existed/will exist) in the world:

  • what phenomena exist (what kinds of things exist?)
  • what is the type of a specific phenomenon (what is this thing?)
  • amount/frequency of phenomena (how much of something is there?)
  • relative amount/frequency of phenomena across different places/times (how much of something is there here vs. there/now vs. then?)
  • what patterns are there in the shared appearance/non-appearance of different phenomena (does this thing usually appear together with that other thing?)

Which of these are descriptive?

  1. About 1.1 million refugees entered Germany during 2015.

  2. The vast majority of these refugees came from Syria and other parts of the Middle East.

  3. “Illegal mass migration undermines the opportunities in life for socially worse off Germans.”

  4. This influx in refugees increased violent crime.

Which of these are descriptive?

  1. About 1.1 million refugees entered Germany during 2015. (descriptive)

  2. The vast majority of these refugees came from Syria and other parts of the Middle East. (descriptive)

  3. “Illegal mass migration undermines the opportunities in life for socially worse off Germans.”

  4. This influx in refugees increased violent crime.

Causal claims:

causal claims:

are claims about the how one phenomena (\(X\)) affects or causes another phenomena (\(Y\)). Causal claims state that \(X\) acts on \(Y\) in some way, not merely that they appear together in some pattern:

  • the effect that one thing or event has on another thing (effects of causes)
  • the cause of some event or thing in the world (causes of effects)
  • the conditions under which some thing or event happens (causes of effects)
  • the process through which one thing affects another (causes of effects)

Which of these are causal?

  1. About 1.1 million refugees entered Germany during 2015. (descriptive)

  2. The vast majority of these refugees came from Syria and other parts of the Middle East. (descriptive)

  3. “Illegal mass migration undermines the opportunities in life for socially worse off Germans.” (causal)

  4. This influx in refugees increased violent crime. (causal)

How to recognize causal claims

(compared to descriptive claims)

Causal claims include some kind of causal verb (or phrase). E.g.:

  • (non-exhaustive list): “causes”, “influences”,“makes happen”, “increases”, “decreases”, “results in”, “was necessary for”, etc.
  • can always be restated as a phrase with a verb, subject, and some object, where subject is the cause and object (or one of the objects) is the affected thing.
  • can always be restated as a phrase like “\(X\) causes \(Y\) to change in some way” or “\(Y\) changes in some way because of \(X\)”

POLL

  1. In 2018, Canada had 0.67 firearms homicides per 100K while the US had 3.14 per 100K.

  2. The United States has more assault weapons per capita and more mass shooting victims than Canada

  3. Canada has fewer firearms deaths per capita than the US because Canada has stricter gun laws.

  4. Americans use guns in self-defense about 2.3 million times per year.

  5. People who openly carry a firearm are less likely to be victims of crimes

  6. Making it easier to legally carry a concealed firearms increases firearms deaths.

POLL (ANSWERS)

  1. In 2018, Canada had 0.67 firearms homicides per 100K while the US had 3.14 per 100K.

  2. The United States has more assault weapons per capita and more mass shooting victims than Canada

  3. Canada has fewer firearms deaths per capita than the US because Canada has stricter gun laws. (causal)

  4. Americans use guns in self-defense about 2.3 million times per year.

  5. People who openly carry a firearm are less likely to be victims of crimes

  6. Making it easier to legally carry a concealed firearms increases firearms deaths. (Causal)

How to recognize causal claims

(compared to descriptive claims)

Causal claims always imply: if we could directly manipulate one thing (\(X\)), then we would see something else (\(Y\)) change

Turn these into causal claims:

  1. In 2018, Canada had 0.67 firearms homicides per 100K while the US had 3.14 per 100K.

  2. The United States has more assault weapons per capita and more mass shooting victims than Canada

  3. Americans use guns in self-defense about 2.3 million times per year.

  4. People who openly carry a firearm are less likely to be victims of crimes

Digression

Causal and Prescriptive Claims

You and your friend agree: the most important ethical goal is minimizing human death (value judgment)

You disagree on what public health measure to take:

  1. We should close in-person schooling (prescriptive claim)

  2. We should close bars and restaurants (prescriptive claim)

Need to know:

Which option prevents the most human deaths? (a causal question)?

Falsifiability

Which claims can science evaluate?

#NotAllEmpiricalClaims testable with science

Falsifiability

an empirical claim is falsifiable

  • if that claim could be shown to be wrong by some empirical evidence.

  • Even if we never conclude that the claim is wrong, there is something, that if we observed it, would prove it wrong

  • e.g. The Earth orbits the Sun.

an empirical claim is unfalsifiable

  • if there is no empirical evidence that could show the claim is wrong.

Falsifiability

Because science considers alternatives/is open to being wrong…

Because science is concerned with objective reality


we can only scientifically evaluate claims that can, could be shown to be wrong empirically.

Only empirical claims that are falsifiable are open to scientific inquiry.

Falsifiability

Contrast with verifiability

If we had an empirical claim, \(H_1\) (\(H\) for hypothesis)

and, if \(H_1\) (claim) were true or valid, then it implies we should make certain empirical observations \(O_1\)

Verification says that

  1. \(H_1 \rightarrow O_1\)

  2. If we see \(O_1\)

  3. Therefore, \(H_1\) is valid

Falsifiability

Many people reject verifiability because many different, incompatible claims are consistent with the same observed evidence

  1. \((H_1, H_2, \ldots, H_k) \rightarrow O_1\)

  2. If we observe \(O_1\)

  3. \(H_1\) is not proven

Falsifiability

If a claim \(H_1\) is falsfiable, there might be observable implication \(O_1\) that, if it were untrue would invalidate \(H_1\). So…

  1. \(H_1 \rightarrow O_1\)
  2. \(not\ O_1\)
  3. Therefore, \(not\ H_1\)

Falsification vs Verification

The difference

Verification looks to see: is there evidence that the claim is right

Falsification looks to see: is there evidence that the claim is wrong

Examples

\(H_1:\) Presidential Election in Georgia was fraudulently stolen from Donald Trump. Allegedly: “counting of [absentee] ballots [in Fulton county] took place in secret after Republican Party observers were dismissed because they were advised that the tabulation center was shutting down for the night.”

Verification

  1. \(H_1 \rightarrow\) If there was fraud, would expect that absentee ballots from precincts on Fulton side of county line broke for Biden more than absentee ballots in precincts in non-Fulton side of county line

Example

\(H_1:\) Presidential Election in Georgia was fraudulently stolen from Donald Trump

Verification?

  1. \(H_1 \rightarrow\) If there was fraud, would expect that absentee ballots from precincts on Fulton side of county line broke for Biden more than absentee ballots in precincts in non-Fulton side of county line.

  2. Researcher finds absentee ballots in Fulton county broke more for Biden than neighboring counties: see here (WARNING)

  3. Therefore, “Fraud in Georgia Election”

Verification?

\(H_1:\) Presidential Election in Georgia was fraudulently stolen from Donald Trump; \(H_2:\) People select residence based on partisanship; \(H_3:\) People select residence based on racial composition of schools

  1. \((H_1, H_2, H_3, \dots H_k) \rightarrow\): Absentee ballots in Fulton side of county line more Pro-Biden than on other side of county line

  2. Researcher finds absentee ballots in Fulton county broke more for Biden than neighboring counties see here (WARNING)

  3. Therefore, \(H_1, H_2, or H_3\) could be valid

Example: Lizard People

\(H_1\): World leaders are actually lizard people who seek to dominate humans

Lizard People: Verification

\(O_1\): World leaders exhibit lizard traits

Lizard People: Verification

We observe \(O_1\):

Lizard People: Verification

\(O_1 \to H_1\): Bow down before your lizard overlords